Portion of heat transfer furnace



FIG. 1 is a perspective view of a portion of the heat transfer furnace;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a referential bottom perspective with the design flipped over and with unclaimed portions removed for ease of illustrating the claimed design.

The broken lines showing on the drawing disclosure are for illustrative purposes only and form no part of the claimed design. The lines consisting of long lines and dots indicate conceptual border lines between the claimed portions and the disclaimed portion. 

We claim, the ornamental design for a portion of heat transfer furnace, as shown and described. 